HOW can i get the coordinate data from an airfoil graphics?

i have a picture of one airfoil, and i wanna get the coordinate of the airfoil to modify the airfoil.

4 Answers

You can obtain all the geometric data from the name itself.
The airofoil name 63-121 was given. .The NACA 63121 profile describes an airfoil with design lift coefficient of 0.9 (0.15*6), the point of maximum camber located at 15% chord (5*3), reflex camber, and maximum thickness of 21% of chord length (21).

Other details are irrelevant
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Answered with a tutorial:

Use a pencil and a graph and work out the Integration and differentiation of the curve. This will give you precise data, or photocopy and import into drawing app with 1:1 scale, depending on software just import or trace

It's simple.
Feature -> Curves -> Curve Through XYZ Points
You can browse Curves: *sldcrv; *txt
Also you can entered manually.

Thank you everyone including Abhilash P,Lukasz Siwiec and Duncan. i have figure the problem out using the software named"plot digitizer". everyone can download it free. it can solve our problem. again thanks everyone and share the software with u.